In recent years, development efforts have been directed to various wireless power transmission systems for wirelessly charging electronic devices and EV devices which involve mobility, e.g., mobile phones and electric vehicles. Wireless power transmission techniques include the electromagnetic induction approach and the magnetic field resonance approach, in which a plurality of coils are placed in opposing relationship, and the electric field coupling approach, in which a plurality of metal plates are placed in opposing relationship. A wireless power transmission system of the electromagnetic induction approach includes a power transmitting device which has a power transmitting coil (power transmitting antenna) and a power receiving device which has a power receiving coil (power receiving antenna). As the power receiving coil captures a magnetic field which is generated in the power transmitting coil, electric power can be transmitted without involving direct contact between electrodes.
Patent Document 1 discloses an example of such a wireless power transmission system.